The aim of this proposal is to investigate the tissue growth enhancement capabilities of fibrous polymeric substrates produced by a novel technique. This technique is capable of producing geometrically defined, nonwoven mats proposed of 0.1- 1.0 mu diameter fibrils. Unlike conventional fibrillation techniques, the proposed technique can utilize a large variety of polymeric solutions as the fibrillation medium and is able to induce polar molecular enrichment on the fibril surface. It is our intent to investigate the use of a "disc insert" configuration, i.e. the fibrous substrate will be configured into a disc of the proper proportions such that is can readily be placed into a untreated vessel. Such a configuration would not only enhance cell growth but also reduce costs and increase ease of post-culture characterization. Our goal in Phase I of this project will be completion of the fibrillation device, production of the fibrous substrates, culture cells on these substrates, and interpretation of results. Four parameters will be varied: Substrate material, fibril diameter, post-fibrillation treatment, and type of cell cultured. Characterization techniques will include FTIR, ESCA, light and electron microscopy, and morphological studies. In Phase II additional materials and parameters will be investigated, work to begin upscaling of the fibrillation device will be initiated, and associated in vitro and in vivo studies performed.